Expandable spinal implant system and method

ABSTRACT

An expandable spinal implant is provided having a frame with a distal wall for retaining an expansion plug such that bone growth promoting material may be introduced to a proximal portion of the implant after expansion. Various implants, systems and methods are disclosed.

The present application is a continuation of U.S. application Ser. No.16/829,421, filed Mar. 25, 2020; which is a continuation of U.S.application Ser. No. 14/885,472, filed Oct. 16, 2015, which are herebyincorporated by reference herein in their entirety.

TECHNICAL FIELD

The present disclosure generally relates to medical devices for thetreatment of musculoskeletal disorders, and more particularly to asurgical system that includes an expandable spinal implant, systems forimplanting an expandable spinal implant, and a method for treating aspine.

BACKGROUND

Spinal disorders such as degenerative disc disease, disc herniation,osteoporosis, spondylolisthesis, stenosis, scoliosis and other curvatureabnormalities, kyphosis, tumor, and fracture may result from factorsincluding trauma, disease and degenerative conditions caused by injuryand aging. Spinal disorders typically result in symptoms including pain,nerve damage, and partial or complete loss of mobility.

Non-surgical treatments, such as medication, rehabilitation and exercisecan be effective, however, may fail to relieve the symptoms associatedwith these disorders. Surgical treatment of these spinal disordersincludes fusion, fixation, correction, discectomy, laminectomy andimplantable prosthetics. As part of these surgical treatments, spinalconstructs, such as, for example, bone fasteners, spinal rods andinterbody devices can be used to provide stability to a treated region.For example, during surgical treatment, interbody devices may beintroduced to a space between adjacent vertebral bodies (the interbodyspace) to properly space the vertebral bodies and provide a receptaclefor bone growth promoting materials.

More recently, interbody devices have been introduced that provideadditional capability beyond static spacing of the vertebral bodies. Forexample, some devices have expansion capability such that the implantmay be introduced to the interbody space in a collapsed state and thenexpanded to produce additional spacing and, in some cases, introduce orrestore curvature to the spine by expanding selectively on only one endor portion of the implant. However, many existing expandable interbodydesigns utilize internal mechanisms that may inhibit the introduction ofbone growth promoting material into the interbody implant by a surgeonafter the implant is expanded. The present disclosure seeks to addressthis and other shortcomings in the existing art.

SUMMARY

In one embodiment, an expandable spinal implant is provided. The implantincludes a frame comprising a proximal wall and a distal wall, whereinthe proximal wall defines a proximal aperture and the distal walldefines a distal aperture. The implant also includes a plug movablydisposed in the distal aperture of the frame and an endplate operablyengaged with the frame and configured to expand outward from the framewhen the plug is moved in a distal direction relative to the frame.

In one alternative embodiment a system is provided including anexpandable spinal implant and an insertion instrument. The insertioninstrument comprises a cannulated outer shaft and a driver shaftremovably and rotatably disposed within the cannulated outer shaft. Theexpandable spinal implant comprises a frame with a proximal wall and adistal wall, wherein the proximal wall defines a proximal aperture andthe distal wall defines a distal aperture. The proximal wall of theframe is configured to receive a distal end of the cannulated outershaft for manipulating the expandable spinal implant. The expandablespinal implant also comprises a movable plug disposed in the distalaperture of the frame, wherein the plug comprises an interfaceconfigured to be operably engaged by a distal end of the driver shaft tomove the plug relative to the frame. The expandable spinal implant alsocomprises an endplate engaged with the frame and configured to moverelative to the frame when the plug is moved by the driver shaft of theinsertion instrument. The driver shaft is also configured to beremovable from the cannulated outer shaft of the insertion instrumentsuch that after the plug has been moved distally relative to the frame,a bone growth promoting material may be introduced into the framethrough the cannulated outer shaft of the insertion instrument. In someembodiments, various other implants, systems and methods are disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is further informed by the specific descriptionaccompanied by the following drawings, in which:

FIG. 1 is a perspective view of one embodiment of an expandable spinalimplant system in a closed configuration in accordance with theprinciples of the present disclosure;

FIG. 2 is a perspective view one embodiment of an expandable spinalimplant system in an open configuration in accordance with theprinciples of the present disclosure;

FIG. 3 is a perspective view of the components shown in FIG. 1 but withone endplate removed to show inner structures of a closed expandablespinal implant system in accordance with the principles of the presentdisclosure;

FIG. 3A is a perspective view of an endplate component in accordancewith the principles of the present disclosure;

FIG. 4 is a perspective view of the components shown in FIG. 1 but withone endplate removed to show inner structures of an open expandablespinal implant system in accordance with the principles of the presentdisclosure;

FIG. 5 is a perspective view of one embodiment of an expandable spinalimplant system in a closed configuration in accordance with theprinciples of the present disclosure;

FIG. 6 is a perspective view one embodiment of an expandable spinalimplant system in an open configuration in accordance with theprinciples of the present disclosure;

FIG. 7 is a perspective view of the components shown in FIG. 5 but withone endplate removed to show inner structures of a closed expandablespinal implant system in accordance with the principles of the presentdisclosure;

FIG. 8 is a perspective view of the components shown in FIG. 6 but withone endplate removed to show inner structures of an open expandablespinal implant system in accordance with the principles of the presentdisclosure;

FIG. 9 is a perspective view of the components of an expandable spinalimplant system including an insertion instrument engaged with anexpandable spinal implant in accordance with the principles of thepresent disclosure;

FIG. 10 is a perspective view of the components shown in FIG. 9 alsoshowing a driver shaft extended through the cannula and in engagementwith the plug;

FIG. 11 is a perspective view of the components shown in FIG. 9 alsoshowing a driver shaft extended through the cannula and in engagementwith the plug to expand the endplates relative to the frame;

FIG. 12 is a perspective view of the components shown in FIG. 9 alsoshowing the driver shaft removed from the cannula;

FIG. 13 is a top view of one embodiment of an expandable spinal implantsystem as used in a PLIF surgical procedure in accordance with theprinciples of the present disclosure;

FIG. 14 is a perspective view of the components shown in FIG. 13 as usedin a PLIF surgical procedure in accordance with the principles of thepresent disclosure;

FIG. 15 is a top view of one embodiment of an expandable spinal implantsystem as used in a TLIF surgical procedure in accordance with theprinciples of the present disclosure;

FIG. 16 is a perspective view of the components shown in FIG. 15 as usedin a TLIF surgical procedure in accordance with the principles of thepresent disclosure;

FIG. 17 is a perspective view of the components shown in FIG. 15 as usedin a TLIF surgical procedure in accordance with the principles of thepresent disclosure; and

FIG. 18 is a perspective view of one embodiment of an expandable spinalimplant system with a single movable endplate and wherein the frame maybe substantially integral with at least one endplate.

DETAILED DESCRIPTION

The exemplary embodiments of the surgical system and related methods ofuse disclosed are discussed in terms of medical devices for thetreatment of musculoskeletal disorders and more particularly, in termsof an expandable surgical implant system that may include an expandablespinal implant, an insertion instrument and/or a method for treating aspine.

In some embodiments, the present system includes an expandable spinalimplant system suitable for insertion from a direct posterior (sometimesreferred to as PLIF procedures) in pairs or singularly and thenexpandable at a distal end in order to impart and/or augment a lordoticcurve of the spine. In some embodiments shown herein, the expandablespinal implant system may also be configured for use in oblique,postero-lateral procedures and/or transforaminal lumbar interbodyfusions (sometimes referred to as TLIF procedures). Additionally, theframe disclosed in various embodiments may be configured to place amovable plug of the spinal implant in a substantially distal positionwithin the spinal implant so as to clear a proximal volume within theimplant for packing with bone-growth promoting materials after theimplant has been inserted and/or expanded using the various techniquesdescribed herein. The frame and other various spinal implant componentsmay also be configured with one or more sidewalls and/or openings todirect bone-growth promoting material to a selected area of anintervertebral or interbody space after the insertion and/or deploymentof the spinal implant. In some embodiments, the spinal implant systemmay also be provided with a tapered distal tip (as viewed from asuperior or top surface) such that the implant is shaped for insertionfrom an oblique approach and placement at a diagonal across anintervertebral or interbody space.

In some embodiments, the spinal implant system may also be employed torestore and/or impart sagittal balance to a patient by increasing and/orrestoring an appropriate lordotic angle between vertebral bodies at aselected level where the spinal implant is implanted and expanded. Insome embodiments, a pair of such spinal implants may be employed frombilateral PLIF approaches and expanded to differing heights to impartand/or restore both a lordotic angle as well as align the spine in thecoronal plane (so as to treat a scoliotic curvature, for example). Insome embodiments, a single such spinal implant may be employed from apostero-lateral TLIF approach and expanded to differing heights toimpart and/or restore both a lordotic angle as well as align the spinein the coronal plane (so as to treat a scoliotic curvature, forexample). In the various embodiments described, the spinal implantsystem may be useful in a variety of complex spinal procedures fortreating spinal conditions beyond one-level fusions. Furthermore, thespinal implant system described in the enclosed embodiments may also beused as a fusion device with an expandable height for tailoring theimplant to a particular interbody disc space to restore the spacingbetween adjacent vertebral bodies and facilitate spinal fusion betweenthe adjacent vertebral bodies.

In some embodiments, and as mentioned above, the present disclosure maybe employed to treat spinal disorders such as, for example, degenerativedisc disease, disc herniation, osteoporosis, spondylolisthesis,stenosis, scoliosis and other curvature abnormalities, kyphosis, tumorand fractures. In some embodiments, the present disclosure may beemployed with other osteal and bone related applications, includingthose associated with diagnostics and therapeutics. In some embodiments,the disclosed spinal implant system may be alternatively employed in asurgical treatment with a patient in a prone or supine position, and/oremploy various surgical approaches to the spine, including anterior,posterior, posterior mid-line, direct lateral, postero-lateral oblique,and/or antero lateral oblique approaches, and in other body regions. Thepresent disclosure may also be alternatively employed with proceduresfor treating the lumbar, cervical, thoracic, sacral and pelvic regionsof a spinal column. The spinal implant system of the present disclosuremay also be used on animals, bone models and other non-livingsubstrates, such as, for example, in training, testing anddemonstration.

The present disclosure may be understood more readily by reference tothe following detailed description of the embodiments taken inconnection with the accompanying drawing figures, which form a part ofthis disclosure. It is to be understood that this application is notlimited to the specific devices, methods, conditions or parametersdescribed and/or shown herein, and that the terminology used herein isfor the purpose of describing particular embodiments by way of exampleonly and is not intended to be limiting. In some embodiments, as used inthe specification and including the appended claims, the singular forms“a,” “an,” and “the” include the plural, and reference to a particularnumerical value includes at least that particular value, unless thecontext clearly dictates otherwise. Ranges may be expressed herein asfrom “about” or “approximately” one particular value and/or to “about”or “approximately” another particular value. When such a range isexpressed, another embodiment includes from the one particular valueand/or to the other particular value. Similarly, when values areexpressed as approximations, by use of the antecedent “about,” it willbe understood that the particular value forms another embodiment. It isalso understood that all spatial references, such as, for example,horizontal, vertical, top, upper, lower, bottom, left and right, are forillustrative purposes only and can be varied within the scope of thedisclosure. For example, the references “upper” and “lower” are relativeand used only in the context to the other, and are not necessarily“superior” and “inferior”.

As used in the specification and including the appended claims,“treating” or “treatment” of a disease or condition refers to performinga procedure that may include administering one or more drugs, biologics,bone grafts (including allograft, autograft, xenograft, for example) orbone-growth promoting materials to a patient (human, normal or otherwiseor other mammal), employing implantable devices, and/or employinginstruments that treat the disease, such as, for example,micro-discectomy instruments used to remove portions bulging orherniated discs and/or bone spurs, in an effort to alleviate signs orsymptoms of the disease or condition. Alleviation can occur prior tosigns or symptoms of the disease or condition appearing, as well asafter their appearance. Thus, treating or treatment includes preventingor prevention of disease or undesirable condition (e.g., preventing thedisease from occurring in a patient, who may be predisposed to thedisease but has not yet been diagnosed as having it). In addition,treating or treatment does not require complete alleviation of signs orsymptoms, does not require a cure, and specifically includes proceduresthat have only a marginal effect on the patient. Treatment can includeinhibiting the disease, e.g., arresting its development, or relievingthe disease, e.g., causing regression of the disease. For example,treatment can include reducing acute or chronic inflammation;alleviating pain and mitigating and inducing re-growth of new ligament,bone and other tissues; as an adjunct in surgery; and/or any repairprocedure. Also, as used in the specification and including the appendedclaims, the term “tissue” includes soft tissue, ligaments, tendons,cartilage and/or bone unless specifically referred to otherwise. Theterm “bone growth promoting material” as used herein may include, but isnot limited to: bone graft (autograft, allograft, xenograft) in avariety of forms and compositions (including but not limited tomorselized bone graft); osteoinductive material such as bonemorphogenetic proteins (BMP) (including but not limited to INFUSE®available from Medtronic plc) and alternative small moleculeosteoinductive substances; osteoconductive materials such asdemineralized bone matrix (DBM) in a variety of forms and compositions(putty, chips, bagged (including but not limited to the GRAFTON® familyof products available from Medtronic plc)); collagen sponge; bone putty;ceramic-based void fillers; ceramic powders; and/or other substancessuitable for inducing, conducting or facilitating bone growth and/orbony fusion of existing bony structures. Such bone growth promotingmaterials (denoted “BG” in some Figures herein) may be provided in avariety of solids, putties, liquids, colloids, solutions, or otherpreparations suitable for being packed or placed into or around thevarious implant 10, 20 embodiments described herein.

The following discussion includes a description of a surgical systemincluding one or more spinal implants, related components and methods ofemploying the surgical system in accordance with the principles of thepresent disclosure. Various alternate embodiments are disclosed andindividual components of each embodiment may be used with otherembodiments. Reference is made in detail to the exemplary embodiments ofthe present disclosure, which are illustrated in the accompanyingfigures. Turning to FIGS. 1-12, there are illustrated components of asurgical system, such as, for example, an expandable spinal implant 10,20 and associated system including an insertion instrument 30.

The components of expandable spinal implant system 10, 20, 30 can befabricated from biologically acceptable materials suitable for medicalapplications, including metals, synthetic polymers, ceramics and bonematerial and/or their composites. For example, the components ofexpandable spinal implant system (including, but not limited to implant10, implant 20, insertion instrument 30), individually or collectively,can be fabricated from materials such as stainless steel alloys,commercially pure titanium, titanium alloys, Grade 5 titanium,super-elastic titanium alloys, cobalt-chrome alloys, stainless steelalloys, superelastic metallic alloys (e.g., Nitinol, superelasto-plastic metals, such as GUM METAL®), ceramics and compositesthereof such as calcium phosphate (e.g., SKELITE™), thermoplastics suchas polyaryletherketone (PAEK) including polyetheretherketone (PEEK),polyetherketoneketone (PEKK) and polyetherketone (PEK), carbon-PEEKcomposites, PEEK-BaSO₄ polymeric rubbers, polyethylene terephthalate(PET), fabric, silicone, polyurethane, silicone-polyurethane copolymers,polymeric rubbers, polyolefin rubbers, hydrogels, semi-rigid and rigidmaterials, elastomers, rubbers, thermoplastic elastomers, thermosetelastomers, elastomeric composites, rigid polymers includingpolyphenylene, polyamide, polyimide, polyetherimide, polyethylene,epoxy, bone material including autograft, allograft, xenograft ortransgenic cortical and/or corticocancellous bone, and tissue growth ordifferentiation factors, partially resorbable materials, such as, forexample, composites of metals and calcium-based ceramics, composites ofPEEK and calcium based ceramics, composites of PEEK with resorbablepolymers, totally resorbable materials, such as, for example, calciumbased ceramics such as calcium phosphate, tri-calcium phosphate (TCP),hydroxyapatite (HA)-TCP, calcium sulfate, or other resorbable polymerssuch as polyaetide, polyglycolide, polytyrosine carbonate,polycaroplaetohe and their combinations.

Various components of spinal implant system 10 may be formed orconstructed material composites, including the above materials, toachieve various desired characteristics such as strength, rigidity,elasticity, compliance, biomechanical performance, durability andradiolucency or imaging preference. The components of expandable spinalimplant system 10, 20, 30, individually or collectively, may also befabricated from a heterogeneous material such as a combination of two ormore of the above-described materials. The components of expandablespinal implant system 10, 20, 30 may be monolithically formed,integrally connected or include fastening elements and/or instruments,as described herein. For example, in some embodiments expandable spinalimplant system 10, 20, 30 may comprise expandable spinal implants 10, 20comprising PEEK and/or titanium structures with radiolucent markers(such as tantalum pins and/or spikes) selectively placed in the implantto provide a surgeon with placement and/or sizing information when theexpandable spinal implant 10, 20 is placed in the spine. The componentsof expandable spinal implant system 10, 20, 30 may be formed using avariety of subtractive and additive manufacturing techniques, including,but not limited to machining, milling, extruding, molding, 3D-printing,sintering, coating, vapor deposition, and laser/beam melting.Furthermore, various components of the expandable spinal implant system10, 20, 30 may be coated or treated with a variety of additives orcoatings to improve biocompatibility, bone growth promotion or otherfeatures. For example, the endplates 140, 150, 240, 250 may beselectively coated with bone growth promoting or bone ongrowth promotingsurface treatments that may include, but are not limited to: titaniumcoatings (solid, porous or textured), hydroxyapatite coatings, ortitanium plates (solid, porous or textured).

Expandable spinal implant system 10, 20, 30 may be employed, forexample, with a minimally invasive procedure, including percutaneoustechniques, mini-open and open surgical techniques to deliver andintroduce instrumentation and/or one or more spinal implants at asurgical site within a body of a patient, for example, a section of aspine. In some embodiments, expandable spinal implant system 10, 20, 30may be employed with surgical procedures, as described herein, and/or,for example, corpectomy, discectomy, fusion and/or fixation treatmentsthat employ spinal implants to restore the mechanical support functionof vertebrae. In some embodiments, expandable spinal implant system 10,20, 30 may be employed with surgical approaches, including but notlimited to: posterior lumbar interbody fusion (PLIF), oblique lumbarinterbody fusion, transforaminal lumbar interbody fusion (TLIF), varioustypes of anterior fusion procedures, and any fusion procedure in anyportion of the spinal column (sacral, lumbar, thoracic, and cervical,for example). Exemplary use of the expandable spinal implant system 10,20, 30 in PLIF and TLIF techniques is shown generally in FIGS. 13-17.

As shown generally in FIGS. 1-8, two exemplary embodiments of anexpandable spinal implant 10, 20 are shown (implant 10 is highlighted inexemplary FIGS. 1-4 and implant 20 is highlighted in exemplary FIGS.5-8). Referring to FIGS. 1-2, expandable spinal implant 10 may comprisea frame 100 comprising a proximal wall 110 and a distal wall 120. Theframe 100 may provide a mechanism for placing an expansion mechanismdistally in the implant 10 such that, once expanded, the implant 10provides ample room nearer the proximal end of the implant (such as atleast partially within the frame 100, for example) for the post-packingof bone growth promoting materials. For example, the proximal wall 110of the frame 100 may define a proximal aperture 111 which may besuitable for receiving at least part of an insertion instrument 30through which bone growth promoting material may be introduced into aproximal portion of the implant 10. Furthermore, the distal wall 120 ofthe frame may define a distal aperture 121 (see FIG. 2, for example)that is adapted to receive a plug 130. As described further herein, theplug 130 may be movably disposed in the distal aperture 121 of theframe.

The expandable spinal implant 10 may further comprise a first endplate140 operably engaged with the frame 100 and configured to expand outwardfrom the frame 100 when the plug 130 is moved in a distal direction D(See FIGS. 3-4). Furthermore, in some embodiments, the expandable spinalimplant 10 may comprise opposing first and second endplates 140, 150 asshown generally in FIGS. 1-2. In some such embodiments of the expandablespinal implant 10, the second endplate 150 may be operably engaged withthe frame 100 and configured to expand outward from the frame 100 whenthe plug 130 is moved in a distal direction D. Furthermore, as shown inFIG. 1, the second endplate 150 may be disposed about the frame 100 andopposing the first endplate 140, wherein the first endplate 140 and thesecond endplate 150 extend from a proximal end of the implant 10 to adistal end of the implant 10 (along the length L of the implant 10) andat least partially enclose the frame 100. A similar structure is alsoshown in implant 20 of FIGS. 5-8, wherein endplates 240, 250 cooperateto at least partially enclose the frame 200 (see FIG. 5, for example).The various endplates 140, 150, 240, 250 may be provided with convexsurfaces in multiple planes to conform to adjacent vertebral bodyendplates (see V1, V2 as shown in FIGS. 14 and 16). It should beunderstood that the surfaces of the various endplates 140, 150, 240, 250could also be constructed with a convexity in only one plane or withoutany convexities. Furthermore, the vertebral body V1, V2 contactingsurfaces of endplates 140, 150, 240, 250 may be provided with variousanti-migration and/or osseointegration features including, but notlimited to: ridges, teeth, pores, and coatings (including but notlimited to porous titanium coatings such as those provided on CapstonePTC™ implants available from Medtronic plc).

FIG. 18 shows an embodiment of an expandable spinal implant 10comprising only a first endplate 140 operably engaged with the frame 100and configured to expand outward from the frame 100 when the plug 130 ismoved in a distal direction D (See FIGS. 3-4). In the embodiment of FIG.18, the second endplate 150 may be integrally formed with the frame 100and/or non-movable relative to the frame 100 such that as the plug 130is moved distally, only the first endplate 140 (hinged to the frame 100via pin 154). In such embodiments, the distal head portion 135 may bemodified to engage the movable first endplate 140 and the static secondendplate 150. For example, as shown generally in FIG. 3A, the movablefirst or second endplate 150 (and/or the complementary endplate 140) maycomprise a ramped surface 153 upon which ramped surface 136 of thedistal head portion 135 may bear as the implant 10 is expanded. The ramp136/153 mechanism may cooperate with a paired lateral post 137 and track145 system (see FIG. 18) in order to optimize the opening and/orexpansion of the implant 10.

Referring generally to FIGS. 1-4, the endplates 140, 150 may be operablyengaged with the frame 100 via a hinge mechanism located near or on theproximal wall 110 of the frame 100. For example, pins 154 may beprovided that engage corresponding pin apertures 112 defined in theframe 100 such that the endplates are operably engaged with and/orhinged relative to the frame 100 such that the endplates 140, 150 may beexpandable relative to the frame 100 by virtue of the cooperation of thepins 154 and pin apertures 112 as the plug 130 is moved distally Drelative to the frame 100 of the implant 10. Similar hinge mechanismsare also shown relative to the embodiments of FIGS. 7-8 comprising pins154 engaged with pin apertures 212 to connect frame 200 with endplates240, 250 in a hinged relationship. While multi-part mechanical hingesare shown in some of the pictured embodiments, it should be understoodthat other types of hinge and/or connection mechanisms may also be usedto operably engage the frame 100 with the expandable endplates 140, 150of the implant. For example, in some embodiments, a “living hinge” maybe utilized wherein the endplates 140, 150 are at least partiallyintegrally formed with the frame 100 at the hinge point but withcut-outs or flex points that allow the endplates 140, 150 to rotateabout the hinge connection. In summary, the frame 100 and endplates 140,150 may be operably engaged in a number of different ways including butnot limited to: integral connections, separable connections,mechanically fixed connections using fastener or adhesives, releasableconnections (including, but not limited to keyways and partially openhinges), and other connection types. In some embodiments, the frame 100and endplates 140, 150 may be integrally formed using additivemanufacturing techniques such as 3D printing or sintering laser/beammelting, casting, extruding, or machined in an integral form usingsubtractive manufacturing techniques from one or more stock materials.

In some embodiments, the frame 100 of the expandable spinal implant 10further comprises at least one side wall 102 engaged with the proximalwall 110 and the distal wall 120. As shown generally in FIG. 3, the sidewall 102 or walls 102, 104 may be configured to space the proximal wall110 and the distal wall 120 along a longitudinal axis (runningsubstantially and/or nearly parallel to the length L) of the expandablespinal implant 10. The side walls 102, 104 may also be configured tocontain bone growth promoting material in a proximal portion of theimplant 10 that may be pre-packed or post-packed into the implant 10 viathe proximal aperture 111. The side walls 102, 104 may cooperate withthe proximal wall 110 and the distal wall 120 to create a four-sidedframe 100 (that may define side apertures as shown in FIGS. 3-4). Insome such embodiments, the frame may define internal threads 103configured to cooperate with an outer threaded surface 131 of the plug130 when the plug 130 is positioned generally proximally relative to thedistal wall 120 of the frame 100.

The frame 100 may be especially useful in some embodiments for placingthe plug 130 in a substantially distal position relative to the overalllength L of the implant 10 such that a distal portion of the implant(within a volume substantially encompassed by the frame 100, forexample) may be open and free to be filled (or “post-packed” withbone-growth promoting materials after the implant has been placed in adisc space between vertebral bodies (see, for example, the placement ofimplant 10, between vertebral bodies V1 and V2, shown in FIGS. 14 and16). As described herein with respect to FIGS. 1, 3, 5 and 7, theimplant 10, 20 may comprise or define a length L along a longitudinalaxis thereof extending from a proximal end 110 thereof to a distal end144 thereof. In some such embodiments, the distal wall 120 of the framemay be disposed at least one third (1/3) of the length L (i.e. at aposition spaced distally from the proximal end 110 by a distance Wasshown generally in FIGS. 3 and 7). In other embodiments the distal wall120 of the frame may be disposed at other fractions of the length L(i.e. at a position spaced distally from the proximal end 110 by adistance W as shown generally in FIGS. 3 and 7) including, but notlimited to, at least 1/10, ⅛, ⅕, ¼, ⅖, ¾, ⅞ and 9/10. In otherembodiments, the distal wall 120 of the frame may be disposed at aposition spaced distally from the proximal end 110 by a distance W asshown generally in FIGS. 3 and 7 wherein the distance W ranges from 0 to100 percent of the distance L, but in some instances distance W is atleast 0.25 of the distance L to provide space in a proximal portion ofthe implant 10 for bone growth promoting material to be adequatelypost-packed into the area defined at least in part by distance W whenthe plug 130 is moved distally. Therefore a proximal portion of theimplant 10 (such as an internal volume defined at least in part by frame100) may be left substantially open and in fluid communication with theproximal aperture 111 of the frame 100 such that a bone growth promotingmaterial may be placed through the proximal aperture 111 of the frame100 after the plug 130 is moved in a distal direction D (see FIG. 3showing the plug in an initial position, and FIG. 4 showing the plugmoved distally to reveal a frame 100 volume left open and in fluidcommunication with the proximal aperture 111).

In other embodiments, as shown relative to the implant 20 in FIGS. 5-8,a single side wall 204 may replace the dual-wall embodiments of FIGS.1-4 to space the distal wall 120 of the frame 100 from the proximal wall110 of the frame. In some such embodiments with a single side wall 204,the frame 200 may be substantially open on one side of the implant 10 toallow for post-insertion packing of bone growth promoting material viathe open side of the frame 200. The “open” or wall-less side of theframe 200 (which may be positioned generally opposite the side wall 204)may also be used to direct and/or contain bone growth promoting materialthat may be introduced to the implant implantation site through theproximal aperture 211 of the frame 200 of the implant 20. As with the“closed” embodiment having two side walls 102, 104, the single side wall204 embodiments may also define internal threads 203 configured tocooperate with an outer threaded surface 231 of the plug 230 when theplug 230 is positioned generally proximally relative to the distal wall220 of the frame 200.

In various embodiments, the plug 130, 230 provided in the expandablespinal implant 10, 20 may comprise a threaded outer surface 131 (seeFIG. 1, for example), and the distal aperture 121 may comprise acomplementary threaded inner surface operably engaged with the threadedouter surface 131 of the plug 130. The threaded outer surface 131 of theplug may be disposed on a proximal end of the plug 130 such that theplug 130 moves distally D as shown in FIG. 4 when the plug 130 isrotated relative to the distal wall 120 of the frame 100. In someembodiments, as shown generally in FIGS. 4 and 8, the frame 100 maycomprise a sidewall 104 connecting the distal wall 120 and the proximalwall 110, wherein the at sidewall 104 comprises a sidewall threadedsurface 103 configured to be operably engaged with the threaded outersurface 131 of the plug 130 (especially when the plug is stillpositioned proximally relative to the frame 100). An alternateembodiment of the sidewall threaded surface 203 is also shown in FIG. 8.Furthermore, the plug 130 may also comprise a distal head portion 135configured to urge the endplate 140 away from the frame 100 with theplug 130 is moved in a distal direction D. The distal head portion 135may be configured in some embodiments (as shown generally in FIGS. 1-4)with a separate structure having ramped surfaces 136 that may beconfigured to interface with complementary ramped surfaces on theendplates 140, 150. For example, as shown in FIG. 3A, the endplate 150(and the complementary endplate 140) may comprise ramped surface 153upon which ramped surface 136 of the distal head portion 135 may bear asthe implant 10 is expanded. The ramp 136/153 mechanism may cooperatewith the lateral post 137 and track 155 system in order to optimize theopening and/or expansion of the implant 10. For example, the ramp136/153 mechanism may provide a leading expansion mechanism that issubsequently assisted by the lateral post 137 and track 155 system toexpand the implant as the plug 130 is moved. Furthermore, the lateralpost 137 and track 155 system may also render the expansion of theimplant 10 reversible by pulling the endplates 140,150 inward towardsthe frame 100 along a relatively smooth ramped incline provided by theramp 136/153 mechanism. Furthermore, the plug 130 may comprise separateconnecting elements 132, 133 such that the distal head portion 135 ofthe plug may be distally movable relative to the frame 100 withoutrotation while a proximal portion of the plug 130 (such as that portiondefining the threaded outer surface 131) is able to freely rotate in thedistal aperture 121 of the distal wall 120 of the frame 100.

In other embodiments, as shown generally in FIGS. 5-8, the plug 230 mayinclude a distal head portion 235 comprising a tapered cylinder. In somesuch embodiments, the distal head portion 235 may be configured torotate with the plug 230 and/or move only distally D relative to theframe 100 as a proximal portion (defining the outer threaded surface231, for example) is rotated relative to the frame 100 to drive the plug230 in the distal direction D. According to some such embodiments, thedistal head portion 235 may be configured to cooperate with a contouredbearing surface 253 (comprising in some instances a ramp and/orfrusto-conical concave surface) defined on an interior surface of theendplates 240, 250.

The distal head portions 135, 235 may be configured in various ways toprovide a lead-in or gradual taper in order to allow for an easierinteraction between the plug 130, 230 and the endplates 140, 150 or 240,250. For example, as shown generally in the partially disassembled viewof FIG. 3 (where the first endplate 140, is removed), the distal headportion 135 comprises a ramp 136 or wedge suitable for urging acomplementary ramped or contoured surface 153 on the inside of theendplates 140, 150 (see FIG. 3A, showing an isolated view of oneendplate 150 with an exemplary ramp 153 formed therein) so as togradually move the endplate 140 away from the frame 100 as the plug 130is advanced distally along the length L of the implant 10. Similarly, inthe embodiments shown in FIGS. 5-8, the distal head portion 235 may betapered to provide a lead-in or frustoconical shape that may beoptimized with a taper that allows for a mechanical advantage to berealized when urging the endplates 240, 250 away from the frame 200. Theresulting open configuration of the implant 20 is shown, for example, inFIG. 6. Furthermore, it should be understood that a variety of rampand/or taper configurations may be used to optimize the interaction ofthe plug 130, 230 with the endplates 140, 150 or 240, 250. Suchconfigurations may include, but are not limited to: sequential ramps ortapered frustoconical surfaces with varying angles; shallow anglesequential ramps or tapered frustoconical surfaces leading into higherangle sequential ramps or tapered frustoconical surfaces (increasing themechanical advantage once an initial expansion of the implant 10 hasbeen achieved), as well as other opening mechanisms (such as the lateralpost 137 and track 155 system shown generally in FIGS. 2-4 that maycombine to assist the ramps 136 (and 153, See FIG. 3A) in expanding theimplant 20).

As shown in FIGS. 2-4, in some embodiments of the expandable spinalimplant 10, the distal head portion 135 may comprise a lateral post 137extending from the distal head portion 135 of the plug 130 andconfigured for cooperating with a corresponding channel 145, 155 definedin the endplates 140, 150. The channels may be angled or partiallyangled to provide additional mechanisms for assisting in the expansionof the implant 10 as the plug 130 is advanced distally along the lengthL of the implant 10. Referring more particularly, to FIG. 2, the firstendplate 140 may define at least one lateral channel 145 configured toreceive the lateral post 137 such that when the plug 130 is moved in adistal direction along the length L, the lateral post 137 of the distalhead portion 135 is moved in a first direction in the lateral channel145 to expand the first endplate 140 outward from the frame 100. Thepost 131 and channel 145 mechanism may also aid in making the implant 10expansion substantially reversible such that when the plug 130 is movedin a proximal direction (i.e. towards the distal wall 110 of the frame100) the lateral post 137 of the distal head portion 135 is moved in asecond direction in the lateral channel 145 to contract the firstendplate 140 towards the frame 100 (which may result in the implant 10returning to the closed or unexpanded configuration shown generally inFIG. 1). This reversible feature, combined with the threaded mechanismof the plug 130 renders the implant 10 capable of being incrementallyexpanded or contracted through a substantially infinitely adjustablerange of motion (bounded only by the length of the plug 130 and thecorresponding bearing surfaces (see 253, FIG. 6, for example) defined bythe endplates of the implant 10)).

In some embodiments, the expandable spinal implant system 10, 20 may beconfigured to be operable with and/or inserted by an insertioninstrument 30 (see generally FIG. 17 for example). In some suchembodiments, as shown in FIG. 9, the expandable spinal implant 10 maycomprise a frame 100 comprising a proximal wall 110 and a distal wall120. The proximal wall 110 may further define a proximal aperture 111and the distal wall 110 may further define a distal aperture 121. Asdescribed herein, one or both of the proximal aperture 111 and thedistal apertures 121 may be internally threaded to receive otherthreaded components. In some embodiments, the proximal wall 110 may beadapted to receive an insertion instrument 30 (or in some cases an innercannula 320 of the insertion instrument 30 as shown in FIG. 9).

As described herein, the expandable spinal implant 10 may also comprisea plug 130 movably disposed in the distal aperture 121, wherein the plug130 comprises an interface 134 adapted to be operably engaged by atleast a portion of the insertion instrument 30 to move the plug 130. Forexample, in some embodiments, the insertion instrument 30 may comprise adriver shaft 330 with a driver on a distal end thereof (such as ahexalobular driver tip). The distal end of the driver shaft 330 may beengaged with the interface 134 of the plug 130 to rotate the plug in thedistal aperture 121 of the frame 100 in order to expand the implant 10.As described herein, expansion of the implant 10 may be achieved by themoving the endplates 140, 150 that are operably engaged by the frame 100and configured to move relative to the frame 100 when the plug 130 ismoved by the insertion instrument 30 (or the driver shaft 330 thereof).

As shown generally in FIG. 17, the driver shaft 330 may be coxiallydisposed inside an inner cannula 320 of the insertion instrument 30.Furthermore, both the driver shaft 330 and the inner cannula 320 may becoaxially disposed inside a cannula 330 of the insertion instrument 30.Each of the driver shaft 330, inner cannula 320 and cannula 310 mayfurther be provided with various manipulation components 330′, 320′ and310′ respectively, so that the various components of the insertioninstrument 30 may be operated and/or selectively manipulated independentof one another to perform various functions relative to the implant 10(as described further herein).

As described herein and shown in the embodiments of FIGS. 3 and 7, theframe 100, 200 may further comprise at least one side wall 104, 204engaged with the proximal wall 110 and the distal wall 120 of the frame100. The side wall 104, 204 may be configured to space the proximal wall110 and the distal wall 120 of the frame 100 along a longitudinal axis(extending parallel to the length L) of the implant 10, 20. In someembodiments, as shown in FIG. 3, the frame 100 comprises a pair of sidewalls 102, 104 spaced laterally apart and engaged with the proximal wall110 and the distal wall 120 of the frame 100 to form a substantiallyclosed area adapted to receive and/or contain a bone growth promotingmaterial that may be placed through the proximal aperture 111 of theframe 100. In some embodiments, the cannula 310 or inner cannula 320 ofthe insertion instrument 30 may be configured to convey bone growthpromoting material through the insertion instrument 30 and into the areadefined by the frame 100 when the implant 10 is in the expanded position(see FIG. 2, for example, showing the plug 130 moved distally forwardand out of the proximal area of the implant 10 defined by the frame100).

In some embodiments the frame 100 may be substantially “closed” withsidewalls as shown generally in FIGS. 9-12. In other embodiments, theframe 100 may comprise a pair of sidewalls 102, 104 with lateralapertures as shown generally in FIGS. 1-4. In other embodiments, asshown generally in FIGS. 5-8, the frame 200 may comprise a unilateral orsingle side wall 204 forming a frame 200 with one “open” lateral side.In some such embodiments as shown in FIG. 8, the frame 200 may beadapted to an least partially contain a bone growth promoting materialBG that may be placed through the proximal aperture 211 of the frame 200and/or direct the bone growth promoting material BG outside of theexpandable spinal implant 20 in a lateral direction between the proximalwall 210 and the distal wall 220 of the frame 200.

FIGS. 9-12 show various configurations of an implant 10 embodiment inuse with an insertion instrument 30 to form an expandable spinal implantsystem according to one embodiment. As shown generally in FIG. 9, thesystem may comprise an insertion instrument 30 comprising a cannula 310(which may include an inner cannula 320 and an outer cannula 310 asdescribed herein) and a driver shaft 330 (see FIG. 10 and FIG. 17)removably and rotatably disposed within the cannula 310. The system mayalso further comprise an expandable spinal implant 10 configured to beoperably engaged with the insertion instrument 30 using a variety ofmechanisms. As described herein, the implant 10 comprises a frame 100comprising a proximal wall 110 and distal wall 120, wherein the proximalwall 110 defines a proximal aperture 111 and the distal wall 120 definesa distal aperture. The proximal wall 110 may be configured to receive adistal end of the cannula 310 (or the middle cannula 320) formanipulating the expandable spinal implant 10. For example, as shown inFIG. 9, the cannula 310 may comprise prongs 311 configured for insertioninto complementary receptacles 114 defined by the proximal wall 110 ofthe frame 100. In other embodiments, the prongs 311 may interact withtabs or slots defined by the endplates 140, 150. The prongs 311 mayinteract with the receptacles 114 to enable a surgeon to manipulate theimplant 10 effectively as it is engaged with a distal end of theinsertion instrument. Furthermore, in some embodiments, the innercannula 320 may comprise a threaded tip 321 configured for operablyengaging threaded inner surface of the proximal aperture 111 of theframe 100. In some such embodiments, the prongs 311 of the outer cannulamay serve as an effective counter-torque device (preventing rotation ofthe implant 10 relative to the insertion instrument 30) as the innercannula 320 is rotated to engage the proximal aperture 111 of the frame100. FIG. 17 shows the insertion instrument 30 in relation to theimplant 10 including manipulation components 330′, 320′ and 310′ of theinsertion instrument. For example, handle 310′ of the outer cannula 310may be used to stabilize and/or manipulate the implant 10 even as theknob 320′ of the inner cannula 320 is rotated within the outer cannula310 such that the threaded tip 321 may be engaged with the proximalaperture 111 of the frame 100 without rotating the implant 100.

As described herein, the implant 10 may be configured for expansion byvirtue of a plug 130 movably disposed in the distal aperture 120 of theframe 100. In some embodiments, the plug comprises a threaded outersurface 131 configured to be engaged with a complementary inner threadedsurface of the distal aperture 120. In some embodiments, as shown inFIG. 9, the plug 130 may comprise an interface 134 configured to beoperably engaged by a distal end of a driver shaft 330 to move (bythreaded rotation, for example) the plug 130 relative to the frame. Thedriver shaft 330 may be coaxially placed within the cannula 310 and/orthe inner cannula 310 and rotatable therein using the driver proximalend 330′ of the driver shaft 330. The driver proximal end 330′ maycomprise a keyed or faceted surface configured for engagement with aquick-release handle (not shown) or a powered driver (not shown) forrotating the driver shaft 330. Furthermore, the plug interface 134 maycomprise a drive receptacle configured to cooperate with a distal end ofthe driver shaft. The drive connection between the driver shaft 330 andthe plug interface 134 may comprise a variety of drive interfacesincluding but not limited to: multi-lobular drives; hexalobular drives;cross or Phillips head drives; straight or “flat head” drives; square orother polygonal drives; and/or combinations thereof.

As described herein, the movement of the plug 130 facilitated by thedriver shaft 310 within the cannula 310 (and, in some cases the innercannula 320) may further cause the movement of an endplate 140, 150operably engaged with the frame 100 of the implant 10 relative to theframe 100 when the plug 130 is moved by the insertion instrument 30.Thus the insertion instrument 30 (or the driver shaft 330 and driverproximal end 330′) may be used to expand the endplates 140, 150 relativeto the frame 100 in order to selectively expand the implant 10 and/orimpart a lordotic movement in adjacent vertebral bodies V1, V2 as showngenerally in FIGS. 14 and 16. The length of the driver shaft 330 may beadjusted to account for the distal placement of the distal wall 120 ofthe frame 100 relative to the length L of the implant 10. For example,the driver shaft 330 may be provided with a length that substantiallyexceeds that of the cannula 310 and/or inner cannula 320 so that thedriver proximal end 330′ remains accessible and engaged with a handle orpowered driver even when the driver shaft 330 remains engaged with theplug 130 of the implant 10 when the implant is in the fully expandedcondition (see FIGS. 14 and 16). This feature may be important insituations where a surgeon wishes to reverse the expansion of theimplant 10 as described further herein with respect to the post 131 andchannel 145 mechanisms of particular implant 10 embodiments.

According to various embodiments, the driver shaft 330 may also beconfigured to be removable from the cannula 310 (and/or the innercannula (if employed)), such that after the plug 130 of the implant 10has been moved distally relative to the frame 100, a bone growthpromoting material BG may be introduced into the frame 100 of theexpandable spinal implant 10 through the cannula 310 (and/or through theconcentric inner cannula 320, when used). The bone growth promotingmaterial BG may be tamped or urged through the cannula 310 or innercannula 310 using the driver shaft 330 or other tamp and/or rod (notshown) sized for slidable insertion through the cannula 310 and/or innercannula 310. A funnel (not shown) or other attachment may also beinserted into a proximal end of the cannula 310 or inner cannula 320(such as at the point near the proximal end or knob 320′ of innercannula 320, as shown in FIG. 17) to facilitate the introduction of thebone growth promoting material BG into the cannula 310 and/or innercannula 320.

FIGS. 9-12 depict exemplary procedural steps for the use of the implantsystem in one embodiment. For example, FIG. 9 shows an unexpandedimplant 10 attached to insertion device 30 using the prongs 311 of thecannula 310 and the distal end 321 of inner cannula 320. The plug 130 isshown engaged with the distal aperture of distal wall 120 of the frameand the plug interface 134 is visible. In FIG. 10, the driver shaft 330is shown extended through cannula 310 and inner cannula 320 and engagedwith the plug interface 134. Referring to FIG. 17, the driver proximalend 330′ may be rotated at this step to drive the plug 130 forward toexpand the endplates 140, 150 relative to the frame 100. FIG. 11 showsthe result of the interaction of the driver shaft 330 with the plug 130and the distal movement of the plug 130 relative to the distal wall 120of the frame 100 to expand the endplates 140, 150 relative to the frame100 of the implant 10. FIG. 12 shows the insertion device 30 stillengaged with the implant 10 but with the driver shaft 330 removed fromthe cannula 310 and inner cannula 320, leaving the cannulas open for theintroduction of bone growth promoting material BG through the insertioninstrument 30 and into a proximal portion of the implant 10 definedgenerally by the now-open interior of the frame 100.

Referring to exemplary FIGS. 13-16, spinal implant system 10, 30 can beemployed with a surgical arthrodesis procedure, such as, for example, aninterbody fusion for treatment of an applicable condition or injury ofan affected section of a spinal column and adjacent areas within a body,such as, for example, intervertebral disc space between a vertebra V1and a vertebra V2. In some embodiments, spinal implant system 10, 30 caninclude an intervertebral implant that can be inserted withintervertebral disc space to space apart articular joint surfaces,provide support and maximize stabilization of vertebrae V1, V2. In someembodiments, spinal implant system 10, 30 may be employed with one or aplurality of vertebra.

A medical practitioner obtains access to a surgical site includingvertebrae V1, V2 such as through incision and retraction of tissues.Spinal implant system 10, 30 can be used in any existing surgical methodor technique including open surgery, mini-open surgery, minimallyinvasive surgery and percutaneous surgical implantation, wherebyvertebrae V1, V2 are accessed through a mini-incision, retractor, tubeor sleeve that provides a protected passageway to the area. In oneembodiment, the components of spinal implant system 10, 30 are deliveredthrough a surgical pathway to the surgical site along a surgicalapproach into intervertebral disc space between vertebrae V1, V2.Various surgical approaches and pathways may be used. FIG. 13 shows anexample of a typical posterior lumbar interbody fusion (PLIF) approachusing the spinal implant system 10, 30 wherein a pair of implants 10 maybe delivered, expanded to impart or restore a lordotic curve (seegenerally FIG. 14), and then post-packed with bone growth promotingmaterial BG after the removal of the driver shaft 330 from the insertioninstrument 30. As shown in FIG. 15, unilateral approaches such as atransforaminal lumbar interbody fusion (TLIF) approach may also be usedto place the implant in a substantially oblique position relative to thevertebrae V1, V2. In such procedures the distal end 144 of the endplates140, 150 may be shaped so that the implant 10 fits within theintervertebral space defined by the extents of the vertebral body V2 asshown in FIG. 15. Furthermore, in oblique placement applications theimplant 10 endplates 140, 150 may also be provided with complementaryoblique contact surfaces shaped to better impart and/or restore alordotic curve as the implant 10 is expanded as shown generally in FIG.16. Furthermore, the endplates 140, 150 of the implant may be providedwith a variety of ridges, teeth, coatings or other surface treatmentssuitable for interacting with and/or securing relative to the adjacentvertebrae V1, V2.

As will be appreciated by one of skill in the art, a preparationinstrument (not shown) may be employed to remove disc tissue, fluids,adjacent tissues and/or bone, and scrape and/or remove tissue fromendplate surfaces of vertebra V1 and/or endplate surface of vertebra V2in preparation for the procedures utilizing the system 10, 30. In someembodiments, the size of implant 10 is selected after trialing usingtrialing instruments (not shown) that may approximate the size andconfiguration of the system 10, 30 (as shown in FIG. 17, for example).In some embodiments, such trials may be fixed in size and/or be fittedwith expansion mechanisms similar to the various implant 10, 20embodiments described herein. In some embodiments, implant 10 may bevisualized by fluoroscopy and oriented before introduction intointervertebral disc space. Furthermore, the insertion instrument 30 andimplant 10 may be fitted with fiducial markers to enable image guidedsurgical navigation to be used prior to and/or during a procedure.

In some embodiments as shown generally in FIGS. 13 and 15, implant 10provides a footprint that improves stability and decreases the risk ofsubsidence into tissue. In some embodiments as shown generally in FIGS.14 and 16, implant 10 provides angular correction, height restorationbetween vertebral bodies, decompression, restoration of sagittal and/orcoronal balance and/or resistance of subsidence into vertebralendplates. In some embodiments, implant 10 engages and spaces apartopposing endplate surfaces of vertebrae V1, V2 and is secured within avertebral space to stabilize and immobilize portions of vertebrae V1, V2in connection with bone growth for fusion and fixation of vertebrae V1,V2.

Components of spinal implant system 10, 30 including implant 10 can bedelivered or implanted as a pre-assembled device or can be assembled insitu. Components of spinal implant system 10, 30 including implant 10may be expanded, contracted, completely or partially revised, removed orreplaced in situ. In some embodiments, one or all of the components ofspinal implant system 10, 30 can be delivered to the surgical site viamechanical manipulation and/or a free hand technique.

In one embodiment, spinal implant system 10, 30 includes a plurality ofimplants 10 (see FIG. 13 for one example). In some embodiments,employing a plurality of implants 10 can optimize angular correctionand/or height restoration between vertebrae V1, V2. The plurality ofimplants 10 can be oriented in a side by side engagement, spaced apartand/or staggered.

In some embodiments, spinal implant system 10, 30 includes an agent,including but not limited to the bone growth promoting materials BGdescribed herein, which may be disposed, packed, coated or layeredwithin, on or about the components and/or surfaces of spinal implantsystem 10, 30. In some embodiments, the agent may include bone growthpromoting material to enhance fixation of implant 10 with bonystructures. In some embodiments, the agent may include one or aplurality of therapeutic agents and/or pharmacological agents forrelease, including sustained release, to treat, for example, pain,inflammation and degeneration.

In one embodiment, implants 10, 20 may include fastening elements, whichmay include locking structure, configured for fixation with vertebraeV1, V2 to secure joint surfaces and provide complementary stabilizationand immobilization to a vertebral region. In some embodiments, lockingstructure may include fastening elements, such as, for example, rods,plates, clips, hooks, adhesives and/or flanges. In some embodiments, thecomponents of spinal implant system 10, 30 can be used with screws toenhance fixation. The components of spinal implant system 10 can be madeof radiolucent materials such as polymers. Radiopaque markers may beincluded for identification under x-ray, fluoroscopy, CT or otherimaging techniques.

In some embodiments, the use of microsurgical, minimally-invasive andimage guided technologies may be employed to access, view and repairspinal deterioration or damage, with the aid of spinal implant system10, 30. Upon completion of the procedure, the non-implanted components,surgical instruments and assemblies (such as insertion instrument 30) ofspinal implant system 10, 30 may be removed and the incision is closed.In some embodiments, the various instruments (such as the insertioninstrumentation disclosed generally herein in FIG. 9 and relatedfigures) disclosed may be provided with fiducial markers or otherelements suitable for use with surgical navigation systems (including,but not limited to the STEALTHSTATION® Navigation system available fromMedtronic plc), such that a surgeon may view a projected trajectory orinsertion pathway of the implants 10, 20 relative to a patient's anatomyin real time and/or in near-real time.

It will be understood that the various independent components of theexpandable spinal implants 10, 20, systems and insertion instruments 30described herein may be combined in different ways according to variousembodiments. As a non-limiting example, the notches 114 shown in FIGS.5-8 with respect to implant 20 may also be added to a proximal end ofthe implant 10 shown in FIGS. 1-4. As a further non-limiting example,the dual apertures 241 a, 241 b, 251 a, 251 b shown in FIGS. 5-8 withrespect to the endplates 240, 250 of implant 20, may also be added tothe endplates 140, 150 of the implant 10 shown in FIGS. 1-4.

It will be understood that various modifications may be made to theembodiments disclosed herein. Therefore, the above description shouldnot be construed as limiting, but merely as exemplification of thevarious embodiments. Those skilled in the art will envision othermodifications within the scope and spirit of the claims in thisdocument.

What is claimed is:
 1. An expandable spinal implant configured to bedeployed between a collapsed position and an expanded position, theexpandable spinal implant comprising: a frame having an aperturetherethrough; a plug movably disposed in the aperture, the plugincluding a first post and a second post; a first endplate pivotallyengaged with the frame, the first endplate including a first channelconfigured to receive the first post, wherein the first endplate isconfigured to pivot outward from the frame as the plug is moved in adistal direction; and a second endplate pivotally engaged with theframe, the second endplate including a second channel configured toreceive the second post, wherein the second endplate is configured topivot outward from the frame as the plug is moved in the distaldirection.
 2. The expandable spinal implant of claim 1, wherein thefirst post positioned in the first channel directly engages portions ofthe first endplate surrounding the first channel, and the second postpositioned in the second channel directly engages portions of the secondendplate surrounding the second channel.
 3. The expandable spinalimplant of claim 1, wherein the first channel is formed in a first wallof the first endplate, and the second channel is formed in a second wallof the second endplate, the first wall being closer to amid-longitudinal axis of the spinal implant than the second wall whenthe spinal implant is in the collapsed position.
 4. The expandablespinal implant of claim 1, wherein the first endplate includes an uppersurface, a first endplate proximal end, a first endplate distal end, andthe first channel extends from a first position positioned adjacent theupper surface to a second position removed from the upper surface andcloser to the first endplate distal end than the first position.
 5. Theexpandable spinal implant of claim 4, wherein the second endplateincludes a lower surface, a second endplate proximal end, a secondendplate distal end, and the second channel extends from a thirdposition positioned adjacent the lower surface to a fourth positionremoved from the lower surface and closer to the second endplate distalend than the third position.
 6. The expandable spinal implant of claim1, wherein the plug comprises a threaded outer surface and a head, thefirst post and the second post are provided on the head, and theaperture of the frame includes a threaded inner surface operably engagedwith the threaded outer surface of the plug.
 7. The expandable spinalimplant of claim 6, wherein rotation of the plug is translated intolinear movement of the head, the first post, and the second post towarda distal end of the implant.
 8. The expandable spinal implant of claim7, wherein the head is at least in part wedged shaped, and the head isconfigured to contact and urge the first endplate and the secondendplate to pivot away from the frame as the plug is moved in the distaldirection.
 9. The expandable spinal implant of claim 8, wherein the headincludes a first ramped surface and a second ramped surface configuredto contact a first inner angled surface of the first endplate and asecond inner angled surface of the second endplate, respectively.
 10. Anexpandable spinal implant configured to be deployed between a collapsedposition and an expanded position, the expandable spinal implantcomprising: a frame having an aperture therethrough; a plug movablydisposed in the aperture, the plug including a head having a firstramped surface and a second ramped surface; a first endplate pivotallyengaged with the frame, the first endplate including a first angledsurface, wherein the first ramped surface of the plug is configured toengage the first angled surface of the first endplate and cause thefirst endplate to pivot outward from the frame as the plug is moved in adistal direction; and a second endplate pivotally engaged with theframe, the second endplate including a second angled surface, whereinthe second ramped surface of the plug is configured to engage the secondangled surface of the second endplate and cause the second endplate topivot outward from the frame as the plug is moved in the distaldirection.
 11. The expandable spinal implant of claim 10, wherein thefirst endplate includes an upper surface, a first endplate proximal end,a first endplate distal end, and the first ramped surface extends from afirst position positioned adjacent the upper surface to a secondposition removed from the upper surface and closer to the first endplatedistal end than the first position.
 12. The expandable spinal implant ofclaim 11, wherein the second endplate includes a lower surface, a secondendplate proximal end, a second endplate distal end, and the secondramped surface extends from a third position positioned adjacent thelower surface to a fourth position removed from the lower surface andcloser to the second endplate distal end than the third position. 13.The expandable spinal implant of claim 10, wherein the first angledsurface and the second angled surface of the head form a wedge shape.14. The expandable spinal implant of claim 10, wherein the plugcomprises a threaded outer surface, and the aperture of the frameincludes a threaded inner surface operably engaged with the threadedouter surface of the plug.
 15. The expandable spinal implant of claim14, wherein rotation of the plug is translated into linear movement ofthe head, the first angled surface, and the second angled surface towarda distal end of the implant.
 16. The expandable spinal implant of claim15, wherein the head of the plug includes a first post and a secondpost, the first endplate includes a first channel for receiving thefirst post, and the second endplate includes a second channel forreceived the second post, interaction of the first post in the firstchannel pivoting the first endplate outward from the frame, andinteraction of the second post in the second channel pivoting the secondendplate outward from the frame.
 17. The expandable spinal implant ofclaim 16, wherein the first post positioned in the first channeldirectly engages portions of the first endplate surrounding the firstchannel, and the second post positioned in the second channel directlyengages portions of the second endplate surrounding the second channel.18. The expandable spinal implant of claim 17, wherein the linearmovement of the head moves the first post within the first channel andmoves the second post within the second channel.
 19. The expandablespinal implant of claim 17, wherein the first channel is formed in afirst wall of the first endplate, and the second channel is formed in asecond wall of the second endplate, the first wall being closer to amid-longitudinal axis of the spinal implant than the second wall whenthe spinal implant is in the collapsed position.
 20. A method formanufacturing an expandable spinal implant, the method comprising:disposing a plug within an aperture of a frame, the plug configured tomove within the aperture and including a first post and a second post;pivotably mounting a first endplate to the frame, the first endplateincluding a first channel configured to receive the first post, whereinthe first endplate is configured to pivot outward from the frame as theplug is moved in a distal direction; and pivotably mounting a secondendplate to the frame, the second endplate including a second channelconfigured to receive the second post, wherein the second endplate isconfigured to pivot outward from the frame as the plug is moved in thedistal direction.